package Homework1;

import java.util.Scanner;

public class Homework2_3 {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		int money = scan.nextInt();
		int number = scan.nextInt();
		int totalFare = money* number;
		if (totalFare>10000) {
			System.out.println("花费" + (totalFare*0.8) );
		}else {
			System.out.println("花费" + (totalFare*0.9));
		}
	}
}
